问优化此查询

EN

SELECT c.city_name, s.state_name
FROM res_geo_cities AS c, res_geo_states AS s
WHERE c.id_state = s.id_state AND(
(
 (c.metaphone_primary IN ($one,$two) OR c.metaphone_secondary IN ($one,$two)) AND 
 (s.metaphone_primary IN ($three,$four) OR s.metaphone_secondary IN ($three,$four))
) OR (
 (c.metaphone_primary IN ($three,$four) OR c.metaphone_secondary IN ($three,$four)) AND 
 (s.metaphone_primary IN ($one,$two) OR s.metaphone_secondary IN ($one,$two))
))
LIMIT 50